PolyhedronIn geometry, a polyhedron (: polyhedra or polyhedrons; ) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices. A convex polyhedron is a polyhedron that bounds a convex set. Every convex polyhedron can be constructed as the convex hull of its vertices, and for every finite set of points, not all on the same plane, the convex hull is a convex polyhedron. Cubes and pyramids are examples of convex polyhedra. A polyhedron is a 3-dimensional example of a polytope, a more general concept in any number of dimensions.
Line segmentIn geometry, a line segment is a part of a straight line that is bounded by two distinct end points, and contains every point on the line that is between its endpoints. The length of a line segment is given by the Euclidean distance between its endpoints. A closed line segment includes both endpoints, while an open line segment excludes both endpoints; a half-open line segment includes exactly one of the endpoints. In geometry, a line segment is often denoted using a line above the symbols for the two endpoints (such as ).
Barycentric coordinate systemIn geometry, a barycentric coordinate system is a coordinate system in which the location of a point is specified by reference to a simplex (a triangle for points in a plane, a tetrahedron for points in three-dimensional space, etc.). The barycentric coordinates of a point can be interpreted as masses placed at the vertices of the simplex, such that the point is the center of mass (or barycenter) of these masses. These masses can be zero or negative; they are all positive if and only if the point is inside the simplex.
BellA bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an internal "clapper" or "uvula", an external hammer, or—in small bells—by a small loose sphere enclosed within the body of the bell (jingle bell). Bells are usually cast from bell metal (a type of bronze) for its resonant properties, but can also be made from other hard materials.
Reciprocal gamma functionIn mathematics, the reciprocal gamma function is the function where Γ(z) denotes the gamma function. Since the gamma function is meromorphic and nonzero everywhere in the complex plane, its reciprocal is an entire function. As an entire function, it is of order 1 (meaning that log log grows no faster than log ), but of infinite type (meaning that log grows faster than any multiple of , since its growth is approximately proportional to log in the left-half plane).
Japanese asset price bubbleThe Japanese asset price bubble was an economic bubble in Japan from 1986 to 1991 in which real estate and stock market prices were greatly inflated. In early 1992, this price bubble burst and Japan's economy stagnated. The bubble was characterized by rapid acceleration of asset prices and overheated economic activity, as well as an uncontrolled money supply and credit expansion. More specifically, over-confidence and speculation regarding asset and stock prices were closely associated with excessive monetary easing policy at the time.
Church bellA church bell in Christian architecture is a bell which is rung in a church for a variety of religious purposes, and can be heard outside the building. Traditionally they are used to call worshippers to the church for a communal service, and to announce the fixed times of daily Christian prayer, called the canonical hours, which number seven and are contained in breviaries. They are also rung on special occasions such as a wedding, or a funeral service.
